Using a new special microscope-microspectrophotometer, it has been possible to isolate single model patterns in rod receptors of frogs and rats for study by passing light through the retina. Comparable first optical studies of goldfish cone receptors have been completed. Microspectrophotometric data should be obtained using this instrument during the coming grant year. Using the improved Stiles-Crawford apparatus, it has been possible to show that retinal receptors across the human retina are aligned with a point approximating the center of the exit pupil of the eye. Emphasis has shifted towards an analysis of factors affecting receptor orientation and possible recovery of alignment after retinal pathology, marked accommodation. The relationship between foveal receptor orientation and interferometrically determined retinal resolution will be reinvestigated. Amblyopic patients will be studied. Studies of psychophysical functions believed to reflect retinal receptive field properties will be pursued. Attempts will be made to further localize the response components of the sustained-cell-like response exhibited by the Westheimer function and the transient-cell-like response of the Werblin-like function. An effect will be made to clarify changes occurring in these functions in glaucoma. In addition, a broad spectrum of patients exhibited retinal pathologies having a known locus will be examined. In keeping with the overall program, an attempt will be made to classify retinally based amblyopia cases.